Lifting-jack.



'PATENTED AUG, 16, 1904.

L. E. HOGKER.

LIPTING JACK.

APPLIOATION FILED MAY 5, 1904.

N0 MODEL.

(:VVENTOI? [baa ML. [fl/41K WITNESSES",

A TTORNE Y S 7 claimed. In the drawmgs, Figure 1 is a perspective- UNITED STATES Patented August 16, 1904.

PATENT OEEIcE.

LlFTlNG-dACK- SPECIFICATION forming part of Letters Patent No. 767,886, dated August 16, 1904.

' Application filed May 5, 1904. Serial No. 206,547. (No model.)

To all whom it may concern.-

Be it known that I, LEWIS EDGAR HOOKER, a citizen of the United States, residing at Montevista, in the county of Rio Grande and State of Colorado, have made certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

My invention is an improvement in liftingjacks, having for an object to provide a novel construction which will be simple, durable, inexpensive to manufacture, free from complication, and easily operated and which can be stopped in any desired position to support the load; and the invention consists in certain novel constructions and combinations of parts, as will be hereinafter described and view of a jack embodying my invention. Fig. 2 is a detail side view from the opposite side of the lifting-lever from that shown in Fig. 1 with the locking-key inserted to secure the lifting-lever in position to support the load; and Fig. 3 is a detail side view, the lifting-lever being partly broken away to show the crossbars of the pawls engaged with the toothed rack.

In the construction shown the upright rackbar or standard A is mounted upon the base B and is toothed at its opposite edges a, the teeth a being in the form of ratchet-teeth, with the operating-shoulders facing upwardly, as shown in the drawings.

The lifting-lever O, which is arranged at one end O to engage beneath the load to be lifted, has the handle O at its other end and is provided between its ends and adjacent the end O with an opening O to fit over the rackbar and with the pawl devices supported on the lifting-lever and engaging with the teeth of the rack-bar in the operation of the invention. In the side Walls of the opening O and near the opposite ends thereof I provide slots O, elongated in the direction of length of the lifting-lever and arranged near the lower edge thereof, as shown. These slots O form guides and ways for the cross-bars D of the pawl devices, the said cross-bars D extending on opposite sides of the rack-bar and in position to engage with the ratchet-teeth thereof in the operation of the jack. These crossbars D are pressed normally toward each other and in contact with their respective teeth a of the rack-bar A, this being preferably effected by means of springs E, which form connections between the opposite crossbars at the ends of the latter and press them toward each other and into contact with the ratchet-teeth, as will be understood from the drawings. Levers F and Gr are secured to the cross-bars D at the ends of the latter and extend upwardly and bear against fulcrum projections F and Gr on the outer sides of the lifting-lever. One set of pawl-levers F may be extended upwardly at f and provided with handle projections f, so they may be readily operated to press the cross-bars D away from each other and out of engagement with the teeth a, the levers G by reason of their arrangement at the ends of the bars D opposite the levers F balancing such levers and aiding in securing the desired movement of the bars D throughout their lengths clear of the teeth a of the upright rack, the levers G serving as equalizing devices at the ends of the bars D opposite the levers F.

In operation by rocking the lifting-lever the same may be caused to travel by the alternate engagement of the opposite cross-bars D with the rack-bar up the upright rack to lift the load, as desired, and by means of a key H, inserted as shown in the drawings, the

lifting-lever can be stopped or locked at any desired point to hold the load on a level. A load can be lowered by simply pressing the levers F toward each other at their upper ends and working the lifting-lever back and forth.. To lower the lifting-lever along the upright rack to any desired point, the crossbars D may be adjusted apart by pressing the upper ends of thelevers Ftoward'each other, setting the cross-bars so far apart that the lifting-lever can be readily moved down the upright rack.

The device can be used for light or heavy lifting and can be easily operated in either instance.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The improvement in lifting-jacks herein described, comprising the upright rack having ratchet-teeth on its opposite edges, the liftinglever provided with an opening to fit over the upright rack and in the opposite walls of said opening near the ends thereof and near the lower edge of the lifting-lever with slots elongated in the direction of length of the liftinglever and located on opposite sides of the upright rack, the fulcrum projections on the opposite sides of the lifting-lever above said slots, cross-bars operating in said slots in the lifting-lever and movable therein into and out of engagement with the ratchet-teeth on the upright rack-bar, springs pressing the opposite cross-bars toward each other, pawl-levers connected with the cross-bars and engaging the fulcrum projections, one pair of pawl-levers at one side of the lifting-lever being extended upwardly to form handles, substantially as and for the purposes set forth.

2. A liftingjack comprising an upright rack-bar, the lifting-lever having an opening fitting over said upright rack-bar, and slots in the opposite walls of said opening near the ends thereof and near the lower edge of the lifting-lever, and elongated in the direction of length of such lever, the crossbars operating in said slots and movable therein into and out of engagement with the teeth of the rack bar, spring devices for pressing the cross-bars into engagement with the teeth of the upright bar, and means for releasing the cross-bars from such engagement, substantially as set forth.

3. The combination of the upright rack-bar, having teeth at its opposite edges, the liftinglever fitted to said rack-bar and pawl devices carried by said lever and including cross-bars carried at their ends on opposite sides of the upright rack-bar by the lifting-lever and engaging between their ends with the rack-bar, substantially as set forth.

4. A lifting-jack comprising the upright rack-bar, the lifting-lever having an opening to fit over the said rack-bar, the fulcrum projections on the said lifting-lever, cross-bars engaging the teeth of the upright rack-bar, levers connected with the cross-bars and engaging the fulcrum projections on the liftinglever, and spring devices for pressing the cross-bars into engagement with the rack, substantially as set forth. Y

5. A lifting-jack comprising the rack-bar having teeth at its opposite edges, a liftinglever fitted to said rack-bar, cross-bars carried by the lifting-lever and engaging between their ends with the rack-bar, releasing devices connected with one end of the cross-bars, and equalizing devices connected with the other ends of the cross-bars.

LEWIS EDGAR HOCKER.

Witnesses:

JAMES S. CAMPBELL, PETER FORNWALD. 

